Muffler or silencer



Jan. 15, 1963 J. sPEcK MUFFLER OR SILENCER Filed Jan. 17. 1961 United States Patent O 3,073,413 MUFFLER R SILENCER Josef Speck, St. Georgenstrasse 216a, St. Gallen, Switzerland Filed Jan. 17, 1961, Ser. No. 83,191 Claims priority, application Switzerland Nov. 10, 1960 Claims. (Cl. 181-64) This invention relates to soundY absorbing equipment for internal combustion engines and more particularly to muiers or silencers which are attached to the exhaust pipe of such engines.

The subject of the invention is an improvement relating to a muler or silencer as described in my Patent No. 2,818,132, dated December 31, 1957. In said patent a mufiier or silencer is disclosed which is attached ,to lthe end of the exhaust pipe of an internal combustion engine, comprising duct means and a bucket wheel rotatably mounted in a chamber having inlet ports, connected to that duct means and an outlet port, communicating with an expansion chamber and outlet means from said expansion chamber to the atmosphere.

It is an object of the invention to provide for the silencing equipment a casing which is positioned and fastened in a housing. The casing walls being spaced from the walls of the housing and the housing is attached to the exhaust pipe of the engine.`

Another object of the invention is to provide for the bladed wheel a bearing arrangement which is situated outside the casing, away 'from Vthe flow of hot gas, in the space between the walls ofthe housing and the walls of the casing. The casing comprising flanges preventing exhaust gas to enter the space between the housing and easing walls. n

Another object of the invention is to provide a hollow shaftfor the bucket wheel. Cool air beingdrawn through the hollow shaft by suction means rotating with the bucket wheel. The air owing through the hollow shaft prevents overheating of thebearing support arrangement.

Still another object of the invention is to provide; for a fly wheel effect of the bucket wheel by the dirnensioning ofthe hub thereof. f

A constructional example of the invention is illustrated in the accompanying drawing, wherein:

FIG. l -is a longitudinal vertical central section through -the noise silencer or muffler according to the invention;

FIG. 2 is a plan view of the silencer without the Vouter tubular housing;

FIG. 3 is a cross-section along the lineIII-III in FIG.

l and FIG. 4is a cross-section along the line IV-IV in FIG. 1

.Referring to the drawing, the silencer shown in FIG- The exhaust gas from the motor enters the opening 29 in the casing 10. This opening communicates with two nozzle or guide passages 18 and which approach the turbine wheel on about diametrically disposed opposite entrance openings 16 and 17 the ow of through 16 and 17 is so directed that the gas in both passages 18 and 20 rotate the blade wheel in the direction.

. The guide ducts 18, 20, for the exhaust gas operating the bladed wheel and the enclosure of the wheel are formed by the casing 10 and a suitably formed plate structure 28 as shown in the figures. The plate structure 28 is fixed to the casing 10 by means of the spacers 26 and 27. The structure 28 provides together with wall parts of the casing 10 two guide ducts 20 and 18. The guide ducts 20 and 18 receive the exhaust gas from the motor via the opening 29; 18 is the main guide duct, converging in ow direction from part of the opening 29 to the enclosure 13 of the bladed wheel 15, 15a and from there on continuing to the side of the outlet opening 23, where it is formed by a partition member 33 adjacent the lower side of the outlet opening 23 by a 180 elbow 19. The member 33 is fastened to the casing wall by means of screws 30 and a spacer 32 which is secured to opposite casing walls. The gas from duct 18 enters into the bladed wheel space through the opening 17 in the opposite direction to the direction of the exhaust from the motor. From the inlet opening 29 into the casing 10l up to the opening 17 of the duct 18 is made of a converging portion followed by a portion of constant cross-sections, as shownin FIG. 1. The auxiliary guide duct 20 enters the space of the bladed wheel on the upper side thereof through 'the opening 16. The duct 20 converges from a part of the entrance opening 29 in the casing 10 up to the opening 16, it is however of smaller through ow crosssection and smaller length than the duct 18 and has no portionof constant cross-section such as duct 18. The gas from-the duct 20 impinges on the buckets 15a so as to Vrotate the bucket wheel 15 in the same direction f as thel gas in the ducts 18 and 19.'

The bucket wheel 1S is mounted on a hollow-shaft 14,0f which bothiends extend through the casing 10. 34 y indicates the respective openings in the casing 10. The

URES l to 4 is made up by a tubular housing or jacket 1 enclosing the silencer unit 10, 11, 12 and 3 6 shown in FIG. 2. The unit is of rectangular shape (see FIGURES 3 and 4) and positioned in the housing .1 by end plates 11 and 12 which prevent the gas to enter the chamber 31, see FIGURES 1 and 2. The casing with walls 10 is braced by traverses 24,25, 26, 27, which permit to build the casing in vtwo symmetrical halves which are firmly fastened to each other by said traverses. The joints of the two halves of the casing are covered by upper and lowerplates and also by the endplates 11 and 12. The casing is'vscrewed to Ythe tubular housing 1 byA means of a screw 9 engaging the threading of a boss 22 formed on two halves of the casing 10.

In the casing 10 a bladed wheel 15 is mounted which is actuated` by the exhaust gas of the motor to which the silencer Vhousing 1 is mounted.

shaft 14 is supported outside of the casing 10 by means of ball bearings 3S. The ball bearing supports consist of cuplike bearing covers 36 firmly fastened to the casing 10. Both covers 36 have a central bore hole 37 registering with the bore of ,the hollow shaft 14.

The hub 4t) of the bucket wheel surrounds the shaft 14 and extends diametrically up to the free ends of the blading 15a. At the intersection of the pipe 38 with the central bore of the shaft 14 the pipe 38 has a cross-hole 39. At rotation of the bucket wheel cool air is drawn from the space 31 in the housing 1 and by centrifigal action `blown through the pipe 38 providing for cooling of the shaft and the bearings. The hub 40 of the bucket wheel is of a relatively large diameter to give it a great mass of round on both-sides of the casing wall 10 the bore hole vto the performance of the motor.

34 for the shaft 14. The ring 42 on the inside of the casing 10 is placed into an annular recess in tha vhub 40 and on the outside of the casing 10 into a ring member 43.

The provision of low friction bearings and a great ily wheel effect of the bladed wheel is also useful with respect of the motor the rotational speed of the bladed wheel is momentarily also increased, while at decreasing speed of the motor, due to the mass of inertia, the bucket wheel will not momentarily but only later, after the passage of By increasing the speed an. interval of time decrease its' rotational speed. Therefore if'it isV necessary for the driver of a carto decrease and at a short interval of time again increase the speed of the vehicle, the rotational speed of the bucket wheel will not change, therefore by its suction effect the density of .the air chargein the motor will Abe increased during the period of deceleration of the motor and will support acceleration of the motor. This feature is of importance in the case with a car muler according to the invention overtaking another. Y Y

I claim: i

1. In a muler, for use in connection with the exhaust pipe of an internal combustion engine, comprising in cornbination a housing defining on its interior a chamber and adapted to be connected with one endk to said exhaust pipe, the chamber communicating with the outside air surrounding said housing, a casing disposed in said chamber having an inlet and an outlet for the exhaust gas and defining an enclosure, a bladed, wheel rotatably mounted in said enclosure, duct means disposed in said casing and operable to conduct gases emanating from said exhaust pipe to said wheel, said duet means comprising a main duct including a one-half turn bend, an auxiliary duct having a cross-section smaller than of saidmain duct, both ducts receiving different amounts of gas from said gas inlet, both ducts terminating at ysaid enclosure for said wheel at about diametrically opposite sides thereof, the gas in the ducts driving said wheel in the same direction,

the gas in said main duct impinging on the blades of theV .Y said wheel, said hub being so dimensioned radially to provide for increased fly wheel effect of the wheel, hear` ingY supports journalling said hollow shaft, said bearing supports being disposed in said chamber in the'Y space intermediatesaid housing v'and saidl casing, sealing'means operable to .restrain the entry of exhaust gas from Vsaid enclosure into said chamber, and blower means connected to said hubY and in tercommunieating with the bore o f said 1 hollow shaft and being ctuatable to draw fresh air from stantially up to the periphery of the free ends of adjacent blades, said pipe vhaving a cross-bore substantially in the middle of itslength formed by the intersection with the bore of said hollow shaft, whereby at rotation of said wheel air is drawn through both ends of the bore of said hollow shaft and blown through and expelled at both ends of said pipe for cooling said shaft and said bearing supports. v

3. A muler according to claim l, said casing Ywalls having openings for the penetration of said shaft and the hub extending up to said openings, an annular recess defined in Jsaid hub around said openings forming a slot with the respective surface of the shaft, said sealing means including packing material insaid slot operable to seal said openings against the escape of gas into said bearing support.

4. A muier according to claim 3, said sealing means furthermore comprising on the outside of said casing and around said openings a container ring to position packing material to ensure the sealing of the openings.

5. A muiller according to claim 1, wherein said bearing supports comprise a cup-like support secured to the` wall of the casing on the outside thereof, low friction bearings supported and surrounded by said cup-like support, said support having a hole registering and intercommunicating with the bore of the hollow shaft for cooling air to be drawn through said shaft.

References Cited in the file of this patent UNITED STATES VPATENTS 

1. IN A MUFFER, FOR USE IN CONNECTION WITH THE EXHAUST PIPE OF AN INTERNAL COMBUSTION ENGINE, COMPRISING IN COMBINATION A HOUSING DEFINING ON ITS INTERIOR A CHAMBER AND ADAPTED TO BE CONNECTED WITH ONE END TO SAID EXHAUST PIPE, THE CHAMBER COMMUNICATING WITH THE OUTSIDE AIR SURROUNDING SAID HOUSING, A CASING DISPOSED IN SAID CHAMBER HAVING AN INLET AND AN OUTLET FOR THE EXHAUST GAS AND DEFINING AN ENCLOSURE, A BLADED WHEEL ROTATABLY MOUNTED IN SAID ENCLOSURE, DUCT MEANS DISPOSED IN SAID CASING AND OPERABLE TO CONDUCT GASES EMANATING FROM SAID EXHAUST PIPE TO SAID WHEEL, SAID DUCT MEANS COMPRISING A MAIN DUCT INCLUDING A ONE-HALF TURN BEND, AN AUXILIARY DUCT HAVING A CROSS-SECTION SMALLER THAN OF SAID MAIN DUCT, BOTH DUCTS RECEIVING DIFFERENT AMOUNTS OF GAS FROM SAID GAS INLET, BOTH DUCTS TERMINATING AT SAID ENCLOSURE FOR SAID WHEEL AT ABOUT DIAMETRICALLY OPPOSITE SIDES THEREOF, THE GAS IN THE DUCTS DRIVING SAID WHEEL IN THE SAME DIRECTION, THE GAS IN SAID MAIN DUCT IMPINGING ON THE BLADES OF THE WHEEL IN A DIRECTION OPPOSITE TO THE EXHAUST DIRECTION, AND THE GAS IN SAID AUXILIARY DUCT IMPINGING ON THE BLADES OF THE WHEEL IN THE EXHAUST DIRECTION, SAID GAS BEING EXPELLED FROM THE ENCLOSURE OF THE WHEEL AND TO THE OUTSIDE OF SAID CASING THROUGH SAID OUTLET, A HOLLOW SHAFT JOURNALLED OUTSIDE SAID CASING AND EXTENDING THROUGH SAID ENCLOSURE AND HAVING AN INTERNAL BORE, A HUB DISPOSED IN SAID ENCLOSURE AND MOUNTED ON SAID HOLLOW SHAFT AND MOUNTING SAID WHEEL, SAID HUB BEING SO DIMENSIONED RADIALLY TO PROVIDE FOR INCREASED FLY WHEEL EFFECT OF THE WHEEL, BEARING SUPPORTS JOURNALLING SAID HOLLOW SHAFT, SAID BEARING SUPPORTS BEING DISPOSED IN SAID CHAMBER IN THE SPACE INTERMEDIATE SAID HOUSING AND SAID CASING, SEALING MEANS OPERABLE TO RESTRAIN THE ENTRY OF EXHAUST GAS FROM SAID ENCLOSURE INTO SAID CHAMBER, AND BLOWER MEANS CONNECTED TO SAID HUB AND INTERCOMMUNICATING WITH THE BORE OF SAID HOLLOW SHAFT AND BEING ACTUATABLE TO DRAW FRESH AIR FROM SAID CHAMBER THROUGH SAID BORE AND TO EXPEL THE AIR CENTRIFUGALLY BETWEEN THE BLADES OF THE WHEEL INTO THE INTERIOR OF SAID ENCLOSURE. 